As the demand for tranceiving data through wireless mobile communication networks grows rapidly, telecom operators begin to study how to achieve higher throughput and more stable Qos in a limited bandwidth.
To enhance the performance of wireless mobile communication systems, widen the bandwidth and improve the spectrum efficiency, the telecom operators may employ, in addition to deploying large base stations and increasing low-cost small base stations, multi-antenna techniques such as massive multi-input multi-output (MIMO) and distributed MIMO to meet the required transmission speed and service quality.
However, the performance of the multi-antenna techniques depends on how the base station acquires the downlink channel information correctly, such that the base station may use it to form constructive synthetic waves, instead of destructive synthetic waves, towards the reception apparatus such as user devices.
Therefore, there is a need to provide methods for transmitting channel information and wireless communication systems using the same, so as to effectively report the base station the downlink channel information.